In the related art, there has been known an image reading device that optically reads an image of a document placed on a contact glass by a reading unit and outputs image data (for example, see Patent Literature 1).
The contact glass is mounted on an upper surface of a scanner housing. The reading unit is received in the scanner housing. The reading unit is installed with a light source that irradiates light toward the document on the contact glass. The reading unit is provided below the contact glass so as to be movable in a sub-scanning direction.
The movement of the reading unit is controlled by a controller. At the time of reading of the document image, the reading unit is moved by the controller from a home position to a moving end set in advance, light reflected from the document is subjected to photoelectric conversion by an image sensor (for example, a CIS sensor, a CCD sensor and the like) during the movement, and the image is read. When the reading operation for the document image is ended, the reading unit is returned to the home position by the controller. In the vicinity of the home position in the scanner housing, a position sensor is normally provided to detect that the reading unit is located at the home position. The position sensor, for example, is configured by a PI sensor.
Furthermore, the scanner housing is mounted with a document pressing unit that is opened and closed with respect to an upper surface of the contact glass, and closed to press the document on the contact glass. The scanner housing is provided therein with an opening and closing detection sensor for detecting the opening and closing of the document pressing unit. The opening and closing detection sensor performs the opening and closing detection by detecting a lower end part of a rod-like member that slides in an up and down direction in interlock with the opening and closing of the document pressing unit.